|
|
Posted by Erland Sommarskog on 04/26/06 16:46
David (david.goodyear@gmail.com) writes:
> Hi, I was hoping someone could confirm the following about the
> following number 2 SQL query:
>
> 1. This extracts the data required given that there is a recording to
> match the records
>
> 2. This should, but im not convinced extract all the remaining records
> that do not have a matched recording, but fulfil the rest of the
> criteria. If not please help...
These conditions seems to contradict each other.
> 3. As the two querys produce the same layout of tables if I did a UNION
> ALL, this should work shouldnt it?
But why? Why not an outer join instead?
> count
> (
> SELECT rec.*
> WHERE rec.whole_phone_number = l.whole_phone_number AND
> rec.last_name = l.last_name AND
> rec.agent = ai.agent_login AND
> rec.campaign = l.campaign
> ) < 1
An EXISTS clause is what you want. This is odd and less effiecient.
--
Erland Sommarskog, SQL Server MVP, esquel@sommarskog.se
Books Online for SQL Server 2005 at
http://www.microsoft.com/technet/prodtechnol/sql/2005/downloads/books.mspx
Books Online for SQL Server 2000 at
http://www.microsoft.com/sql/prodinfo/previousversions/books.mspx
Navigation:
[Reply to this message]
|